Sampling

Sampling

1. Random Sampling

   • It is a method that there is an equal chance of anyone being selected
   • If a random sample of a particular group was needed, then they would have to random selected a lot of people
   • If the population is very large, random samples would be expensive and therefore an element of convenience sampling could be used

2. Stratified Samping

   • When a specific group that has particular characteristics needs to be surveyed, a stratified sample is appropriate
   • A typical stratified sample could be based on gender or age, or have a similar characteristic such as hair colour

3. Cluster Sampling

   • This involves selecting a small group that represents a much larger group
   • Collecting information about how people will vote often uses cluster sampling to save time and costs

4. Systematic Sampling

   • This is sampling by formula
   • Using a set approach which involves selecting every hundredth person, this suggest the sample is fair and not subject to any bias

5. Convenience Sampling

   • This is the most frequently used type of sampling. It is a quick and easy way to collect data
   • The sample of people asked is more likely to be local or appear to roughly fit the desired group
   • They may even be friends of the collector, who knows they will answer the required questions. Therefore it lacks reliability and accuracy

6. Quota Sampling

   • This type of sampling concentrates on gaining enough information, by selecting individuals to mirror the characteristics of the total population or required segment
   • The key consideration is to gain a sufficient number of people in each segment required
   • For example, if 25% of the population being studied is over 50 years old, then the quota should reflect this.

7. Factors to consider when Sampling

   • It is important to weigh up the need for reliable information
   • It is important to weigh up the cost of collection
   • It is important to weigh up the budget available
   • It is important to weigh up how quickly the information can be collected
   • It is important to weigh up how up to date the information is